The goal of this project is to develop an easy-to-use, microcomputer-based software application to help researchers perform ROC studies. The software will have facilities for aiding the researcher in all phases of an ROC study, including experiment design, setting up for test sessions, conducting test sessions, analyzing results and generating reports. The primary requirements are that the software: l) is easy to use; 2) streamlines design and implementation of ROC studies; 3) makes ROC analysis accessible to a wider audience of researchers than presently; 4) encourages correct use of statistical methods. Phase I of this project saw the successful completion of a prototype version of the software, named ROC Assistant, which enables the user to enter a case list, run test sessions and produce an ROC curve. During Phase II we will continue with this success by, producing three more versions of ROC Assistant. These versions will progressively incorporate further enhancements to the software, including additional statistical analysis functions, features to help with experimental design and an online help facility. We will emphasize ease of use when developing the software and will follow guidelines developed by Apple Computer, Inc. for design of the user interface. We will evaluate our software by conducting beta tests both in- house and in conjunction with consultants at the University of Arizona Department of Radiology. Additional beta testers will be solicited at professional meetings during Phase II.